mod_http_oauth2: Rudimentary support for scopes (but not really) We don't support limiting access, but this change will inform the client what permissions the created token has (e.g. is the user an admin or not). There is some work in progress on real scope support.

This module writes out a traceback to `traceback.txt` in Prosodys data
directory (see `prosodyctl about`) when the signal `SIGUSR1` is
received. This is useful when debugging seemingly frozen instances in
case it is stuck in Lua code.